[squid-users] Error 503 accessing Instagram/facebook via IPv6

[marcelorodrigo at graminsta.com.br]

Hi,

I have been using squid for several years and am very grateful for the 
solution.

Since last 3-4 days my customers haven't been able to access 
www.instagram.com and Facebook throug IPv6s that were already working as 
proxies for years.

I only get 503 error after a time out.
The strangest thing is that I can connect 20-30% of the attempts.

I didn't make any changes to the VPSs.

I switched IPv6s provider to a totally different subnet, changed several 
equipments, but it didn't work at all.

If I access through the same VPS using the same IPs as squid is running 
using curl command but not going through the proxy It works.

But through Squid it no longer accesses as before.
This only happens with v6 IPs. On V4 Squid runs normally.

I upgraded to Ubuntu 20.04 and Squid 5.2-10 but everything remains the 
same.

My agency depends on it and I've already lost half of my clients.
Could you please help me, even if I have to pay for support?